thomson



(ModeL) 2 SheetsSheet 1.

E. THOMSON.

ELECTRIC LAMP MECHANISM. No. 303,898 Patented Aug. 19, 1884.

(ModeL) 2 SheetsSheet 2.

E. THOMSON.

ELECTRIC LAMP MECHANISM.

' No 303,898. Patented Aug. 19, 1884.

may 6%%%- UNITED seam ATENT omen.

ELIHU THOMSON, OF N EWV BRITAIN, CONNECTICUT, ASSIGNOR TO THETHOMSONIIOUSTON ELECTRIC COMPANY.

ELECTRIC-LAMP MECHANISM.

SPECIFICATION forming part of Letters Patent No. 303,838, dated August19, 1884.

' Application filed June 8, 12481. (Mmleln To aZZ whom it may concern.-

Be it known that I, ELIHU THOMSON, a citizen of the United States,residing in the city of New Britain, county of Hartford, State ofConnecticut, have invented certain Improve ments in Electric-LampMechanism; and I do hereby declare that the following is a descriptionthereof.

My invention relates to an electric lamp in which carbon electrodes areused for producing an arc; and it consists of combinations of devicesfor securing certainty of operation, regularity of arc length, and theprevention of Opeucircuiting when several lamps are arranged in series.I make use of an electromagnet and armature imparting movement to aclamp for lifting the upper carbon and establishing the are. I alsoemploy a shunt or derived circuit magnet to close a set of contactsforming a shunt of small resistance around the lifting-magnet coils, ora portion thereof, and arranged so as to cause a very delicate feedingof the electrodes as consumed. I also employ a very effective device forforcing the approach of the carbon electrodes in case of the failure ofsaid carbon electrodes to feed.

Iv will proceed to describe my invention by reference to theaccompanying drawings.

Figure 1 is a front view of the regulating mechanism of an electric lampembodying the substantial features of my iiiventiolnFig. 2, a figurepartly in section showing the devices for lifting the carbon-rod It indetail; Fig. 3, a top view or plan of the clamp D D, Fig. 1. Fig. 4shows the relation between the liftingmagnet and its armature. Fig. 5 isa plan of said armature and magnet-pole. Fig. 6 isa peculiar arrangementof dash-pot for checking the movement of the lifting-armature. Figs. 7,8, 9,10, and-11 are views of an improved safety device for forcing theapproach of the electrodes when the arc resistance becomes abnormallygreat. I

In Fig. 1 the parts are shown supported in the interior of an iron frameor box, the carbon-rod R passing vertically through its center. Anelectro-magnet, M, t aversed by the circuit current or direct current isarranged so as to attract an armature, B, pivoted as .is lifted orlowered.

shown. The magnet and armature are shaped, as will be described inconnection with Figs. 4t and 5, though this construction is notessential to the operation of the lamp, a plain flat armature and flatpole of the magnet M being also suitable. movements of the armature B aclamp, D D, This clamp serves to seize the carbon-rod R and establish anare when lifted, and to allow said rod to slip through it when lowered.Figs. 2 and 3 show the preferred construction of thelifting-clamp D D.An arm, C, Fig. 1, connects the armature B to adash-pot or othercheck-1notions, as may be preferred. The clectro-magnet K of highresistance is a shunt or derived circuit around the arc, and thevariations of its power,.acting vin opposition to a spring, WV, upon itsarmature A, serve to close or open a set of contacts, 1) g, whichconstitute a shunt of small resistance around coils of M, so as byshunting current from such coils toweaken the magnets power.

The magnets 19 1 .may be simply a single pair of contacts, or may beconstructed as de scribed in my Patent No. 261,790, and constitute avariable-resistance shunt. The construction of the contacts whereby thisresult may be effected is shown in Figs. 12 and 13, where the contact 1)is divided like a comb or brush, and has its teeth so arranged as tocome successively into contact with a block, q, of carbon. indicated bythe numeral 5,'Fig. 1, and the wire which includes magnet M and isshunted is indicated by the numeral 6. The action of thederived-circuitmagnet K and contacts 1) q in shunting the feed-magnet M issubstantially the same as in my patent before referred to. A smallresistance-coil or resistance, 1', is provided partly as apreventive'o'f spark during the closing and opening of said contacts Bythe upward and downward The shunt-wire around magnet M is,

p g. This resistanceis connectedto thebranch 5 at the points indicated,so as to form a circuit for the current in 5 around said contacts. \Vhenthe contacts are open, the branch 5 is a'shunt of high resistance around6 and the magnet M; but when the contacts are closed the resistance iscut out. I also make use of this resistance r for a novel purpose.changing its amount, as by changing itslength or size of wire composingthe coil, or the material of the coil, or by otherwise changing theresistance of r in any manner, I am enabled to adapt the power of thelifting-magnet to varying strengths of current used to operate the lampwithout changing the winding of the magnet M as to size of wire,convolutions, &e. The device for adjusting the resistance, as hereshown, consists ofthe well-known arrangement of a switch moving over aseries of contacts connected to the resistances at various points,whereby a greater or less length of the resistance may be included inthe circuit 5 around the magnet M. NVhere a current of large volume orstrength is used the resistance r is made less, so as to permanentlydivert more current from the magnet, and thus adjust its lifting-powerto the proper amount, and where acurrent of small volume or strength isemployed, the resistance r is made great, so as to force the currentthrough the magnet and thus give it the proper power. It is thus,without otherwise changing the construction of the lamp, I adapt it torun upon greater orless current strength bymcrely changing the amount ofthe resistance r.

I do not limit myself as to the manner or means of varying theresistance 2'. It may be applied to any kind of lifting or regulatingmagnet in an electriclamp, no matter whether the variations of power insaid magnet for producing a feed are brought about by the automaticshunt herein described, or by other and well-known arrangements of saidmagnet itselt'in the circuit. The resistance r constitutes in any case apermanent derivation around the coils of the regulating magnet throughwhich the direct current passes, and acts to divert current from saidmagnet and to modify its power, so as to adapt it for use in anycircuit.

The poles of the magnet K are shaped with respect to the armature A,moving near thereto, so as to give a nearly uniform attractive force invarious positions when a constant current is circulating through thecoils of the magnet K. This result is accomplished by the tapering ofthe poles, as shown in Fig. 1. A second set ofcontaets, t a, whichremain closed during normal. operation of the lamp, constitute a shuntor short circuit around an electro-magnct, S, which latter acts to bringinto o )eration a safety device, :fully described in connection withFigs. 7, S, 9, l0, 1].. The contacts in are opened when the armature Bfully retires from its limits of position during normal feeding of thecarbon electrodes. A stop or projection, V, is provided for opening thecontacts 1. a.

The general circuits are as follows: Entering at X, the circuit is toand through eon tacts ta when armature B is raised or when said contactsare broken through the magnet S. After passing through contacts I a ormagnet S the circuit divides, as shown, one path being through themain-circuit magnet M to the carbon-rod, the are, and out at Y, theother being to one side of the set of contactsp and q, and, when thelatter are closed, through the same to the upper carbon, or through themagnet K to the point Y, magnet K being, as indicated and as usual, in aderived circuit around the carbons. The resistance r is in a brancharound the contacts 1) q, and forms the whole or a portion of the path.for the current in the branch from 1 at around magnet M, according asthe contacts 1) q are open or closed. On establishing a current thearmature B is lifted and the contacts melosed. The clamp D I) lifts therod B. and establishes the are at *When the arc has elongated slightly,the contacts 1) q are closed by the increased at traction of the shuntmagnet or coil K upon its armature A, thus diverting sufficient currentfrom the magnet M, releasing the arma ture B, which descending opens theclamp II) D and allows the carbon-rod to feed down ward. The contacts 1)q and L a may be both operated directly by the armature A of theshunt-magnet K, as indicated in Fig. Lt. In this latter case thecontacts 2 (I are first closed, after which closure the contacts Mareopened by a further movement of the shuntarmature A, so that the firstaction of the shunt is to feed the electrodes, the second actionbeing tobring into operation the magnet S to insure their approach if thefeeding otherwise fails.

In Fig. 2,1; is the lilting-armature, to or by which the clamp-body I)is pivoted or sup ported. The movable toe or clamp ll), pivoted asshown, rests against the rod R, and

has an elongated portion, to which one end of a spring, S, is attached,while the other end of the spring is attached to a fixed support. G is afixed bushing through which the rod 11. is guided. Bushing G issupportedby an arm, F", secured to the lamp frame or casing. Bushing Galso bears a stop, F, secured to a curved arm, F", projecting from F",arranged to open the elampjaw 1), when the armature B and part I) arelowered to the position as in the figure. The rod R then slidesgradually through the clamp I).

It will be seen that the view of the parts I) G B, Fig. 2, is at rightangles to thatin Fig. 1. The spring S is seen in front of llig. 1. Thestop F is merely a projection from the bushing G, secured to the lampbox: and frame. The clamp-body l), as shown, is pivoted to the armatureB, which is perforated for the free admission of the carbon-holding redIt. The clamp I) therefore moves with the armature B up and down, whilethe spring S holds the toe D against the red It, when said too is not incontact with the stop F, as when the clamp l.) is lifted by the armatureB.

In Fig. 3 the relations ot'the parts I) and l) of the clamp are morefully shown, the too or jaw D occupying a portion of the opening in theclampbody D, through which the rod It passes.

In order to equalize the magnetic effect of IIO IIS

the magnet M upon its armature B in different positions, its pole N ispreferably allowed to project through the armature B, and it has acur-ved'face made upon it, as shown. The

'pole is shown as square in horizontal crosssection, and ascorresponding with a similar square opening in the armature B in Fig. 5,and in Fig. 4 as tapered or chamfered to a curved form. The circularoutline of the core from which it projects is indicated in Fig. 5 by thecircular dotted line.

Fig. 6 is a dash-pot, which I prefer to em ploy to check the movementsof the armature B and render them more gradual. The rod G, Figs. 1 and6, is provided with a piston, P, fitting more or less loosely in thetube P. The base H of the lamp-box has projections I 1,

allowing a slight play of the dash-pot body in a vertical direction, anda spring, S may be provided to assist in holding the dash-pot in contactwith the base H during normal operation. I find the slight play affordedto the dash-pot useful in assisting the quick closing of the clamp Dimmediately after the rod It has slid through it, or a feeding act-ionhas been exerted. An inverted tubular neck, 0, is provided forpreventing escape offluid from the dash-pot when the lamp is inverted orlaid upon its side, sufficient space being provided around the neck 0 tocontain all the fluid when the lamp is in an inverted position.

Fig. 7 is a full-sized view of the safety-magnet, called into action toviolently force the carboirrod R downwardly when the contacts t a areopened by a failure to feed normally.

The device by which this is accomplished is a spring, or any suitableactuating device, normally held out of action, but released when thecarbon fails to feed and the are abnormally lengthens. lVhen the springor other power acts on the upper-carbon carrier, a clampclutch, or anydevice that may grasp the upper-carbon carrier and pull it downforcibly, is arranged to be actuated by said spring at the proper time.Said clamp or clutch is also, by preference, provided with a suitabledevice for normally holding its jaw or other engaging surface away fromthe surface of the carrier, so that the latter may move freely upward aswell as downward. The construction of these parts may be infinitel yvaried without departing from the invention, the gist of which consistsin combining with a carboncarrier a spring or other actuating powernormally held out of action upon said carrier while the lamp is workingproperly, but automatically released and allowed to actuate the carrierby any suitable means when the arc becomes abnormally long or the carbonfails to feed for an extended period. Vhen the spring acts upon thecarrier through a clamp or clutch, as is usually the case when it isarranged to force the carbon that feeds toward the are, said clamp orclutch may be constructed and arranged as follows: Surrounding thecarbonrod R is a collar, T, or sliding tube, provided piece, f, borne bythe tube T. Projections K,

one or more, are placed upon the tube T, by which it may be upheldagainst the action of a spring, Q, tending to draw the tubeT for ciblydown. *Engaging upon the projection K is a catch, 1), supported oractuated by, or I otherwise arranged so as to be under the control ofthe magnet S, and the catch 1) upholds the projection K and the tube T,in virtue of its position under the projection K. A small projection,70, also holds the jaw J open, so as to leave the rod It free in theposition of the parts, as shown in the figure. The magnet S is hung upona lever, L, pivoted vertically under-the piece K to the frame H. Aspring, Z, supports the magnet S in position, leaving a small intervalbetween its polar extremity and the iron case H, as shown. 7 Theposition of the parts as here shown in Fig. 7 is given at the startingof the lamp, and is always maintained during normal operation, and itwill be seen that the carbon-rod is free to descend, the jaw J beingprevented from locking upon the rod R by-the projection 7c.

Fig. 8 is a plan of the parts in the same position as in Fig. 7. R is acarbon-rod5 J, the jaw; 7.", its stop or projection; S, the magnetcorc;b, projection or catch borne by the magnet and engaging under thecatches K of the tube T. The parts K and b may be duplicated on theother side of the rod R, as shown in dot ted lines.

Fig. 9 is another view of the parts shown in Fig. 7 or end elevation,the tube T inclosing the rod R, and spring Q attached to the projectionK, the catch b under the part K, the lever L upon which the magnet S isswung, as shown.

lVhen the contacts t a, Fig. 1, are opened by the retirement of thearmature B beyond its limits, during normal operation due to a failureof the clamp D to feed the carbon-rod, the magnet S is rendered activeby the passage of the current and attracts itself to the sides of theframe H of iron. The position it then occupies is seen in Fig. 10. Thespring Z is extended and the magnet S tipped over, so as to withdrawfirst the stop in, leaving the jaw J free to engage upon the rod R, andsecond, the projection 11 is withdrawn from the under side of the catchK. In this position the tube T is left without any upholding-support,and is borne downward with considerable force by the spring Q or its ownweight, if sufficient. However, the jaw J having looked upon the rod Itby the aid of the spring Z, the tube T cannot descend without bringingthe rod R down with it, and as the spring Q ma be of an i desired strenth an a )roaeh' of the carbon is thus secured and the circuit is keptfrom being broken by a failure of the lamp to feed. Moreover, the actionof the spring Q is continued through a considerable space, and therebythe carbons are held together until the defect in the feeding action isproperly remedied. Should the tube T descend, as in Fig. 11, and bringthe jaw J into contact with the step c, thej aw is again opened and thered It is again free to descend through the piece T. After the tube Thas been re leased, the attendant, finding that it has been so releasedand has brought the carbons to gether, can restore it to its originalposition Fig. 7, by simply raising it from below the frame H, attend tothe lamp, examine into the causes of the safety-magnet having beencalled into action, and restore the lamp to its normal workingcondition. "When the lamp is reearboned the magnet S is set, and is inthe main circuit, owing to the fact that the contacts t a are opened bythe armature. \Vhcn the current begins to flow, however, the magnet Macts and closes the contacts t a before magnet S has time to act, themore prompt action of magnet M and armature 13 taking place because atthis time the carbonrod is not supported by the armature, and theretracting-force acting on magnet S is much stronger than that acting onarmature l3. Magnet S might be made more sluggish in action than M bymeans well known in the art as, for instance, by making its core long orby making-its wire of higher resistance than that of M. Vheu thecont-acts t a are closed the current is diverted from S, which cannotthen act until the armature falls back, so as to open the contacts for aeom 'iarativcly prolonged interval.

Various changes in the relations of the parts of the safety device maybe used to effect the same resultviz., to bring a stored force, as astretched spring, into action consequent on an increased power of theshunt clectro-magnot, when the are otthe lamp has attained an abnormallength.

I do not limit myself to any particular form or construction of devicefor imparting a post tive movement to the carrier when it fails to feedproperly, since the gist of my invention consists in employing asupplemental actuator that may, when called into action, give a positivethrust to the carbon or carrier, said actuator being normally preventedfrom op erating during the usual feed movements of the carbon, and inautomatically bringing the same into operation to force the carbonstogether, it from any cause the feed fail to take place and the arebecome abnormally long.

I claim 1. The combination, in an electric lamp, ofa clamp or clutchapplied so as to grasp the carbon carrier and impel it toward theopposite carbon,a spring or equivalent actuating device connected to theclamp, and a catch or detent for normally holding said clamp or clutchout of engagement with the carrier, as and for the purpose described.

2. The combination, with a spring-actuated impelling clutch or clamp forthe carbon-carrier, of a catch or detent normally preventing the samefrom engaging with the carrier, and an electro magnet that controls thecatch.

3. The combination, with the carbon-can rier in an electric lamp, of animpellingcluteh or clamp for forcing the carrier toward the oppositecarbon, a suitable catch or detent for holding said clutch or clamp outof action, an eleetro-magnet controlling the detent, and a suitablecireuit-controller, whereby the llow of an electric current through saidmagnet is controlled so as to cause a release of the detent by theelectro-ma-gnet whenever the are be comes abnormally long.

1. The combination, with the carbon-carrier in an electric lamp, of aclamp or clutch applied in the manner described, so as to force thecarrier toward the opposite carbon. at detent or catch for normallyholding said clamp or clutch out of action during feed of the carbon,and releasing devices for releasing said clamp or clutch, controlled byan eleetro-magnot connected to the lamp-circuit in the manner described,so as to be ai't'ectcd by an abnormal increase in the length of are.

5. The combination, in an electric lamp, of

a (an-boirearrier, a sleeve or guide for the carrier, a clamping toe orjaw mounted on the sleeve, and arranged to lock the carrier so as toimpel the same toward the opposite carbon, an aetuatingspring connectedto the sleeve, and suitable catches or steps for holding theclamping-toe and the acti'iating spring for the sleeve out of action.

6. The combination of the earbolrcarrier, a spring-actuated sleeve orguide carrying a clamping toe or jaw, a stop for holding the clampingtoe or jaw out of engagement'with the carrier, a catch or stop engagingwith the sleeve, and means for automatically and simultaneous] ywithdrawing said stops, as and for the purpose described.

7. In a safety device for an electric lamp, an-electro-magnet, S,shunting contacts'l'or the same closed during normal feed of thecarbons, and a clutch or clamp and actuating spring therefor, normallydetained by said magnet during feed of the carbon, and arranged in themanner described to grip the earbon rod and force the carbons togetherwhen the carbons fail to feed properly.

8. A safety device in an electric lamp, eonsistiug ot' a clamp or clutcharranged to act upon the carbon-holder, a powerful spring upon saidclamp or clutch, a catch or stop adapted to be removed from said clutchdevice by an electro-magnet, and a set of contacts forming a shuntaround said magnet, substantially as described.

9. The combination, with the carboncarrier, of an actuating clamp orclutch applied so as to force the carrier toward the opposite carbon, adisengaging-stop normally holding the same out of engagement, means forwithdrawing the same when the arc becomes ab- IIO normally long, and asupplemental disengaging-stop for disengaging the clamp when it hascompleted its throw.

10. The combination of the electro-magnet S, arranged as described,catches b is, clampsleeve T, springs q, for the purpose of effecting anapproach of the carbon electrodes when said magnet is energized bysuitable devices brought into action by the formation of an arc ofabnormal length.

11. The combinatiomwith the feed-controlling devices in an electriclamp, of a dash-pot both members of which are movable for a slightdistance in the same direction with the part of the feed-controllingdevices from which they are actuated.

12. The combination, with a feed clamp or clutch for an electric lamp,of an actuating lever or support, and a dash-pot one member of which isconnected tosaid lever, while the other member is movable longitudinallyfor a slight distance with the first when the lever or support moves ina direction to cause the clamp to close and engage with thecarboncarrier.

13. The combination, with the feed-controllingclamp or clutch in anelectric lamp, of a dash-pot one member of which is connected with thefeed-clamp, so as to retard its movement, while the other member isfree, so as to be capable of following the retarding: movement of thefirst, so as not to oppose its movement, and suitable stops for limitingthe movement of the free member.

14. The combination, with a feed controlling clamp or clutch in anelectric lamp, of a dash-pot whose piston is connected with said clamp,and a dash-pot cylinder resting loosely on the floor of the lamp orother support, and provided with stops set to allow a slight movement ofsaid cylinder with the piston.

15. The combination, with the regulating magnet or armature, of adaslrpot movable longitudinally with its piston, as and for the purposedescribed.

16. In an electric lamp, the combination of a regulatingmagnet helix,and adouble shunt consisting of a permanentlyclosed circuit around saidhelix, containing an adjustable resistance, and anautomatically-variable resistance acting in accordance with variationsin the arc length.

17. The combination with a carbon-carrier in an electric lamp, of asupplemental actuating device for forcing an approach of the carbonsnormally out of engagement with the carrier while the feed of thecarbons is taking place in the proper manner, and means for bringingsaid actuating device into operation whenever from any cause thecarbon-carrier sticks and produces an arc of abnormal length, so as toforce the carbons together and preserve the circuit.

18. The combination, substantially as described, with a carbon-carrierfor an electric lamp, of carbon separating and feeding mechanism, asupplemental actuating'spring for forcing the carbons together throughany suitable supplemental device, means for holding said spring-out ofact-ion during normal feed of the carbons, and a releasing device forautomatically releasing the spring, so that it may force the carbonstogether if from any cause the car bon or carbon-carrier fail to feedproperly.

19. The combination, with the carbon-carrier for an electric lamp, ofcarbon separating and feeding mechanism, and a supplemental actuatingdevice for grasping the carbon or carrier and forcing the carbonspositively together whenever the feed fails to take place in the normalway.

20. The combination, with a carbon or car bou-carrier, of a supplementalactuating device, a catch or detent normally engaged there with, to holdsaid actuating device out of action, and means for disengaging saidcatch or detent upon an abnormal increase in the length of are, so as topermit said actuating device to force the carbon into contact with theopposite carbon.

21. The combination, with the carbon separating and feeding mechanism inan electric lamp, of a supplemental device for grasping the carbon orcarbon-carrier and carrying it toward the opposite carbon and held outof

